This application claims the priority of International Application No. PCT/DE2005/000364, filed Mar. 4, 2005, and German Patent Document No. 10 2004 011 615.6, filed Mar. 10, 2004, the disclosures of which are expressly incorporated by reference herein.
The invention relates to a rotary friction welding machine.
Friction welding is a widespread joining method for the fabrication of gas turbines. Friction welding is considered a part of the so-called pressure welding process, whereby in terms of friction welding a differentiation is made, among other things, between so-called linear friction welding, rotary friction welding and so-called friction stir welding. The present invention relates to so-called rotary friction welding in which rotationally symmetrical components are joined to one another or connected to one another via friction. In rotary friction welding, a first component rotates, while the other component is stationary and is pressed with a specific force against the rotating component. In this case, the joining surfaces of the components being connected to one another adapt to one another via hot forging.
Rotary friction welding is performed on so-called rotary friction welding machines, whereby, according to the prior art, the rotating component is positioned on a rotating spindle and the stationary component is positioned on a non-rotating spindle. According to the prior art, a disk flywheel or a flywheel mass body is allocated to the rotating spindle. The flywheel mass body and the rotational speed of the rotating spindle are coordinated with the components being connected to one another, particularly with the materials of the components being connected to one another. In the case of components that are made of nickel-based alloys, large or heavy flywheel masses and low rotational speeds of the rotating spindle are used. In this case, the following interrelationship applies: large or heavy flywheel masses are coupled with a low rotational speed of the rotating spindle and small or light flywheel masses are coupled with a great rotational speed of the rotating spindle.
In rotary friction welding machines known from the prior art, when there is a change in the components being connected to one another, particularly a change in the material composition of the components being connected to one another, it is necessary to adapt the rotary friction welding machine by exchanging or adapting the flywheel mass body or the disk flywheel to the modified conditions. In this case, it is necessary to perform expensive set-up work on the rotary friction welding machine according to the prior art. Thus, according to the prior art, the flywheel mass bodies are positioned or removed using a crane. This type of set-up work requires a lot of time and causes downtime for the rotary friction welding machine.
Starting from this, the object of the present invention is to create a novel rotary friction welding machine.
According to the invention, several flywheel mass bodies are positioned on the rotary friction welding machine, wherein the flywheel mass bodies cooperate with the first rotating spindle such that at least one of these flywheel mass bodies can, as needed, be brought out of operating engagement or into operating engagement with the first rotating spindle, wherein both the flywheel mass bodies that are in operating engagement with the first rotating spindle and the flywheel mass bodies that are out of operating engagement with the first rotating spindle are positioned on the rotary friction welding machine. In so doing, the rotating spindle itself can serve as a flywheel mass body. According to the present invention, it is possible to adapt the rotary friction welding machine to changing components without expensive retooling or set-up work.
According to an advantageous development of the invention, several flywheel mass bodies are allocated to the first rotating spindle such that the flywheel mass bodies when in operating engagement with the first spindle rotate jointly with the spindle and when out of operating engagement with the first spindle are stationary as compared with the spindle. In this connection, at least one of the flywheel mass bodies is rigidly connected to the first rotating spindle, while the or every other flywheel mass body is rotatably mounted on the spindle in such a way that the or every flywheel mass body that is rotatably mounted on the first spindle can be selectively coupled to and uncoupled from the or every flywheel mass body that is rigidly connected to the first spindle. This embodiment of the rotary friction welding machine has a particularly simple structure.
According to an alternative advantageous development of the invention, the several flywheel mass bodies are allocated to a flywheel mass shaft, wherein the flywheel mass shaft is coupled to the first rotating spindle via a transmission gear. The first spindle that bears the rotating component can be coupled via the transmission gear to a flywheel mass shaft that rotates more quickly. In this case, smaller flywheel masses that rotate at a greater rotational speed can be used in order to generate the same torque.
According to another alternative advantageous development of the invention, the flywheel mass bodies can be moved back and forth between two magazine halves such that the flywheel mass bodies are in operating engagement with the first spindle in a position that is inserted into a first magazine half and out of operating engagement with the first spindle in a position that is inserted into a second magazine half. Both magazine halves are preferably embodied as a revolver magazine, wherein the two magazine halves have recesses to accommodate the flywheel mass bodies.